Date:   Tue, 30 Nov 2021 08:55:36 +0100
From:   Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>
To:     Rob Herring <robh@kernel.org>
Cc:     Toan Le <toan@os.amperecomputing.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Andrew Murray <amurray@thegoodpenguin.co.uk>,
        =?utf-8?B?U3TDqXBoYW5l?= Graber <stgraber@ubuntu.com>,
        stable@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] PCI: xgene: Fix IB window setup
Message-ID: <YaXY+E2Uto4O43c3@rocinante>
References: <20211129173637.303201-1-robh@kernel.org>
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In-Reply-To: <20211129173637.303201-1-robh@kernel.org>
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Hi,

> Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup")
> broke PCI support on XGene. The cause is the IB resources are now sorted
> in address order instead of being in DT dma-ranges order. The result is
> which inbound registers are used for each region are swapped. I don't
> know the details about this h/w, but it appears that IB region 0
> registers can't handle a size greater than 4GB. In any case, limiting
> the size for region 0 is enough to get back to the original assignment
> of dma-ranges to regions.

A small nitpick: it would be "X-Gene" in the above as per Applied Micro's
(or rather MACOM Technology Solutions these days, I suppose) product line
naming.

> @@ -465,7 +465,7 @@ static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
>  		return 1;
>  	}
>  
> -	if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) {
> +	if ((size > SZ_1K) && (size < SZ_4G) && !(*ib_reg_mask & (1 << 0))) {
>  		*ib_reg_mask |= (1 << 0);
>  		return 0;
>  	}

Thank you!

Reviewed-by: Krzysztof Wilczyński <kw@linux.com>

Also, thank you Stéphane for testing!  Much appreciated!

	Krzysztof